Method of manufacturing artificial stone



Patented Dec. 17, 1329;

GEORGE Ev KENDALL, F KALAMAZOO, llIICI-IIGAN METHOD or MANUFACTURINGvanarrator inszronn N0 Drawing.

The object of this invention is to provide an improved method andprocess of manufacture which Wlll secure an artificial stone with verydense smooth surface having the.

appearance of being polished in imitation of marble or any other cutface and polished I stone, and the improved product which may imitatemarble or granite.

Objects pertaining to details will appear 1 from the detaileddescription to follow.

The invention is defined in the claims.

My improved method or process consists in providing a mold with a faceplate for making the face of the stone which is impervious to moistureand smooth. This may be a glass sheet or sheet metal or any othermaterial. I-then apply to the face plate a mixture of Portland cement,preferably one part cement to one part sand, using an excessive amountof'water far beyond what is necessary to set the cement. I mix the sameand stir it so that it is of a paint-like con' sistency, with allcolloids fully developed,

and apply it to the smooth face of the mold with a brush, thoroughlyworking it into contact with the said face, and placing the mold faceplate down so that none of the moisture will drain off.

If it is desired to produce patterns in the stone in imitation of marbleor other irregularity, I apply the pattern to this painted coating onthe back side, forcing it. through the layer with a blunt pointedimplement so that it penetrates to the face of the mold, 3 leaving acharacteristic colored mark, ap-

plying in this way any coloring matter. Of course, to secure the mostpermanent results a mineral pigment is required.

When the surface has been thus prepared, 49 I fill the balance of themold with a grout, preferably of four parts sandto one part cement,making it very wet so that it pours. As soon as this has partially set,or immediately if that is expedient, I place the mold face down so thatit will accumulate water on'the face plate in excess of'that needed forthe setting of the cement. I then cover the whole with damp sand ofsufficient volume and thickness, or otherwise protect the same, toprevent evaporation. of the design.

Application filed March 5, 1926. Serial its; 92,636.

' moisture, retaining the same and allowing the cement to set,preferably for a period or not lessgthan ten days. A shorter period se-I cures only fair results and perfect results are not secured under tendays. -At the end of that time Iremove the block from the mold. It isnecessary .to start atone edgeof the face,

plate and open it very carefully to admit air', which causes the film''of water to divide and separate, leaving a; surface which is .as

smooth as ordinary polished marble. This J surface must not be. touchedbecause ltis appear to be of a crystalline cha-racteiy'but amorphous orwaxy, as it can-be readily dented without breaking. The kind of Portland cement used is not material, so far as I have observed. Ifimitationmarble is desired, I use white cement. If granite is desired, I use theordinary gray cement. Either of these'c'an be colored as desired andwith any suitable design. A very effective plain stone is securedwithout injecting in the I wish to claim theinvention broadly andspecifically, and also the design and the coloring in the mannerdescribed, because the effect is very similar to the effect of naturalmarble or stone.

Having thus described my invention, What I claim as new and desire tosecure by Letters Patentv is: I

1. The process of making artificial marble or stone consisting inproviding a mold with a face plate of flat, smooth, impervious,waterproof material, applying thereto with the face plate down arichpaint-like, wet mixture of cement with, a brush toidevelop the colloidsand completely and closely cover the surface, injecting through themixture suitable color designsby scratching with a blunt pointedinstrument, thereafter cover ing the whole with grout of substantiallyfour parts sand to one part cement, wetting the same thoroughly, placingthe mold with face plate down, and covering the whole. with damp sand toretain the moisture, al-

lowing'it to stand a suflicient to fully separating the face plate fromone edge carefully to insure the separation due to the film of Waterformed between the face plate and the stone, as specified.

2. The process of making artificial marble p or stone consisting'inproviding a mold with a face plate or fiat, smooth, impervious,waterproof material, applying thereto with the face plate down3'IIlCl1,;PZLlI1iZ-llk6, Wet I 'mixture of cement with a brush todevelop the colloids and completely and. closely. cover the surface,thereafter covering the Whole with grout of substantially four partssand to one partcement, wetting the same thoroughly, placing the moldwith face plate down,and Covering. the whole with damp sand "to retainthe moisture, allowing the same to stand a sufficient time to fully set,then removing it from the mold, and separatingthe face plate 'fromoneedge carefully to insure the separation due to the film of water formedbetween the face plateand the stone, as specified.

In witness whereof I have hereunto set my (hand. 7 I

' GEORGE KENDALL.

